SIR: I have the honor to report that a small expedition sent out by me last night to Clark's Ferry, 17 miles above this point, on the French Broad, has returned this morning with 7 prisoners infantry and cavalry, belonging to South Carlina and Tennessee regiments. Two of the prisoners (one a brigade forage master), belonging to Dibrell's brigade, of Armstrong's division and both on a separate examination, say that their brigade is at Dr. Boyd's, 2 miles from the mouth of Chucky, on the Dandridge road and within half a mile of French Broad River. They also say that the only other brigade in their division (Harrison's) is, they believe, somewhere near Dibrell'; also that their division left Panther Springs nearly a week ago, on Monday or Tuesday.

The forage master is quite well informed, and says he issued forage to 800 men for duty in his brigade; that there are but two brigades in Armstrong's division (Dibrell's and Harrison's) and two in Morgan's; that Harrison's brigade may be a very little larger than Dibrell's; and that one brigade of Morgan's division is not as large as Dibrell's; that his own regiment, the Eighth Tennessee has 140 men only; that their cavalry horses are in good serviceable condition, getting 24 ears of corn per day now, when on full rations; that all the forage about Panther Springs and Morristown and in the intermediate country to the French Broad and Chucky is exhausted, also on the banks of French Broad and Chucky on the other side, and that they are now relying for forage on this side of the French Broad and Chucky, getting it across by canoes and by fording. He also says that Armstrong's and Morgan's divisions of cavalry were both engaged in the last fight at Mossy Creek. One of the infantry prisoners was acting commissary sergeant of his regiment (the Second South Carolina Infantry, Kershaw's brigade, McLaws' division). His brigade and division were at Russellville when he left them day before yesterday, at which time Hood's division was at Morristown. He came across the river to run a mill near Clarke's Ferry, the three mills their division had about Russellville not being sufficient. He confirms the report about McLaws being relieved and sent to Richmond.

I had the honor to send a report to General Elliott yesterday via Headquarters Army of the Ohio, at Knoxville, it being impossible to get it across the river in consequence of the ice. In that report I stated that Armstrong's division of cavalry had probably three brigades. I now believe he has but two, and I do not think Martin's entire cavalry force for duty without Jones' to exceed 4,000, or with Jones' to exceed 6,000. (I inclose a copy of that report.)